AP BIOLOGY

Detailed explanation-1: -Humans have two sets of chromosomes. Homozygous and heterozygous are terms that are used to describe allele pairs. Individuals carrying two identical alleles (RR or rr) are known as homozygous. While individual organisms bearing different alleles (Rr) are known as heterozygous.

Detailed explanation-2: -The (RR) genotype is homozygous dominant and the (rr) genotype is homozygous recessive for seed shape. In the image above, a monohybrid cross is performed between plants that are heterozygous for round seed shape. The predicted inheritance pattern of the offspring results in a 1:2:1 ratio of the genotype.

Detailed explanation-3: -The presence of two different alleles at a particular gene locus. A heterozygous genotype may include one normal allele and one mutated allele or two different mutated alleles (compound heterozygote).

Detailed explanation-4: -If someone possesses both the dominant and recessive alleles for tongue rolling, we would write his or her genotype as “Rr”. The capital R shows that there is one dominant allele for tongue rolling, and the lower case r represents the other, recessive allele.